Carbonyl ylides from aldehydes and carbenes

The interaction of rhodium carbenoids with carbonyl compounds as a method for the synthesis of tetrahydrofurans

“…Reactions of carboalkoxycarbenes with carbonyl compounds were described as early as 1885 [17] and the structures of the dioxolane products were proposed in 1910 [18]. The early investigations by Huisgen and de March [19] with dimethyl diazomalonate (1) revealed that in reactions with benzaldehyde, a mixture of isomeric 1,3-dioxolanes (2) was formed (Scheme 1) when Rh 2 (OAc) 4 , Cu(acac) 2 or CuOTf was used as the catalyst. Since the initial Huisgen report, the catalytic generation of carbonyl ylides from diazo compounds has developed into a powerful reaction for organic synthesis [20][21][22].…”

Intermolecular Reactions of a Foiled Carbene with Carbonyl Compounds: The Effects of Trishomocyclopropyl Stabilization

“…[80][81][82][83][84][85][86][87][88][89][90] There are fewer examples of the intermolecular variant. [91][92][93][94][95][96] Still, less is known about the reactions of carbonyl compounds with nucleophilic carbenes. [71][72][73] Although carbonyl compounds are themselves amphoteric, they should react as electrophiles 9 with nucleophilic carbenes.…”

The Synthesis of Solvent-Free Glycidic Esters from Diazoesters and Carbonyl Compounds Catalysed by Lanthanide Triflates

“…[15] The use of boron trifluoride etherate, triethyl oxonium tetrafluoroborate, tin(II) chloride, titanium(IV) chloride, zinc dichloride or antimony(V) chloride usually yields only the corresponding homologation adducts in the reaction between EDA and aldehydes or ketones, [16] although α,β-epoxy esters have been obtained as side products in the boron trifluoride etherate catalysed reaction between acetone and EDA at low temperatures [17] or by thermal or Cu I - promoted decomposition of methyl diazomalonate in the presence of benzaldehyde. [18] The only example of the selective formation of glycidic esters starting from diazo compounds is the reaction catalysed by methylrhenium trioxide reported by Espenson and Zhu in 1995, [19] although with some substrates the process was not selective and led to the formation of ∆ 3 -1,3,4-oxadiazolines as side products in 5Ϫ21% yield.…”